Imbalances between both complexes can be due to overexpression of EZH2 in undifferentiated cancers, but most commonly occur in cancers by mutations of members of the SWI/SNF complex, such as ARID1A and SMARCA4 that together with SMARCA2 is the ATPase subunit of this tumor-suppressing complex. The gene discussed is SMARCA1; the disease is neoplasm.